Rotary boring-drill.



GJA. HUMASON.

ROTARY BORlNG DRILL.

APPLICATION FILED DEC. 23, 1918.

Patented Dec. 30,1919.

2 SHEETS-SHEET l.

Cfmfwife 51. Num man, INVENTOR.

Myx/WARM 12 i 5 A TTORNEY.

, (LA. HUMASON.

ROTARY Bumm; DRILL.

'APPLICATION FILED 050.23, 191s. y

K Patented Dec. 30,1919.

'2 SHEETPSHEET 2. 1

Gsmnvi@ LJumason, INVENTOR.

BY 'Ufwf- HIS ATTORNEY.

UNITED y sTATEs PATENT oFFioE,

GRANVILLE ALLIsON HUMASON, OF HOUSTON, TEXAS, AssIGNon OF ONE-HALF TO JOHN w. PARKER, OF HOUSTON, TExAs. a

.ROTARY BORING-DRILL.

To all whom t may concern.'

Beit known that I, GRANVILLE A. HUMA- soN, a citizen of the United States, residing at Houston, Harris county, Texas, have invented a certain new and useful Improvement in Rotary Boring-Drills, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in rotary boring drills of the collapsible type sometimes called underreamers.

The object of my invention is to provide a drill which may be introduced into the Well and again withdrawn without also removing the drill stem.

Another object is to provide a drill of the character referred to, which will be collapsible and yet strong and serviceable and capable of drilling in both rock and softer formation. f

Another object is to` provide means to hold the 'bit securely in expanded position but which will also allow the bit to be readily collapsed when it is desired to withdraw the.

same from the well.

While drilling wells in many formations it is a diiiicult or impossible matter to with-f' dra-w the drill stem or casing from the well without causing the walls of the wel] to cave in and lill up the portion of the well already dug. Wheny the well is deep the whole well is sometimes ruined thereby.

'This is especially true in quicksand or heaving shale. ln such formatlonsit is lusually necessary to go to great expense to freeze the walls of the well to prevent caving when the drill is withdrawn for repairs or sharpening.l

The manner in which I contemplate overcoming these obstacles will be apparent in the specification which follows and will be .set forth with particularity in the claims.

Referring to the drawings forming a part f invention. Fig. 4 isa broken detail showing ythe means for locking my bit in oper- Speccation of Letters Patent. Patented Dec. 30, 1919. i

Application filed December 23, 1913. Serial No. 267,894. I

ative position taken at right angles to the position of the same illustrated in Fig. 2. Fig. 5 is a transverse section taken on the line 5-5of Fig. 1. Figf is a simila-r section taken on the line 6 6 of Fig. l. Fig. 7 is a transverse sectional view of a drill stem showing the use of a different design of cutter for the drill head. Fig.

v8 is a bottom plan view of the bit shown in Fig. 7. Fig. 9 is a transverse section taken on the line 9 9 of Fig. 1. Fig. 10 is a transversesection of the lower end of the drill stein-used with my invention.

My collapsible bit is composed of a head i shaped like a flattened cylinder at the lower end and longitudinally divided to provide two side sections 1, each having a reduced upper shank 2. The two flattened sides of the reduced shank 3 extend upwardly about midway of said shank, the upper section 5 of the shank being cylindrical in shape so as to t closely within the drill stem when expanded intoy the position shown in Fig. l. The construction of theY said shank 2 with cylindrical upper portion-5, leaves a shoulder 4C at the lower end of the cylindrical portion, which is adapted, when the bit is expanded into operative positionto rest upon a flange 8 on the lower end of the drill stem 9 in which the bit is adapted to operate. The flange 8, as shown particularly in Figs. 8 and 9, projects inwardly from the lower end of the casing to form a shoulder upon which the bit may rest. The flattened face 3 of the shank below the Vshoulder 4 thusfits non rotatably between the two flattened sides of the ange 8, causing the bit to -rotate with the drill stem. The head 1 is divided longitudinally along a central plane Gand has rotatable cutters 7 of which I have shown two in number on the lower end thereof. The exact shape and type of cutters which may be used can be varied and may be of any ordinary construc-.

tion, the same forming no part of my invention.

fThe upper end of the shank 2 of the bit is beveled inwardly toward the divided plane 6, as shown at '10. This provides a wedge-shaped seat on the upper end of the 'bit to serve in expanding the head as will later described. The interior faces vof the two side sections composing the head 1 are recessed inwardly at 12 to provide a sliding keyway for amo Vised portion 13 of a central section 14, hich constitutes an.V important feature of my bit.

The centralA removable section 14 is an elongated bar rectangular in cross section as shown in Fig. 6 and extending upwardly for some distance within the lower section of drill pipe 9./ This rsection ispivoted at its upper endv to .a pin 15 and has at its lower i end two downwardly projecting' arms 16 which are bored tovpiovide a seat for a pin. 17 upon whichjare mounted a plurality of means of a cable or rod having a means for detachable connection with the threaded niprotatable cutters 18. At a point spaced above the lower cutters 18 on said shaft is fixed a flattened block or plate 19. `This l block, as willvbe noted,.is fixed at a point a suficient distance to place the cutters 18 in, Ioperating position, the block 19 will contactwith the upper surface of the head. A

sufficient distance above thev cutters to ac- I ycommodate the length of the head 1 of the bit so that when the central section 14 is moved downwardly between the sections 1, a

shoulder 11 is also provided in such position as to contact with the flange 8 of the pipe 9,-Whenthe bit isfoperating.

Projecting .upwardly from the two sidel sections of the head1 are bolts or rods 2O having enlarged heads 21` thereon. vThese rods-20 are adapted to fit slidably within openings 22 within the plate 19. The @holes 22v are somewhat elongated laterally collapsed. The vtwo lateral facesof'the cento providespace for` movement inwardly of the two sides of the head when the bit is tral section '14 are recessed slightly immediately above the plate 19, as shown at 23', thus providing a space to accommodate the heads 21 ofthe ytwo rods 20 when the bit is in collapsed position, shown in Fig. 2.

The upper end of the lower pipe section i 9 of the drill stem is threaded lwith a special coupling 24 which serves to connect the said lower section with an ordinary drill stem 25..v The coupling member 24 is somewhat elongatedl and has an intermediate annular `recess 26 there-inA to accommodate the expansion of a toggle joint by whichthe central section 14 of the bit is operated and secured. llhistoggggle -jointiscomposed of two -shortsections27 pivoted at their lower ends to the pin'15 onthe section 14 and, at a point somewhat spaced .from their upper ends, to pins 28.- The pins 28 serve also for n the pivotal connection of two somewhat similar upper. arms 29 of the said toggle joint. `The upper ends of the sections 29 are pivoted to the pin Y3() connecting the vsaid'secti'ons 29 with the upper attaching block 31 which serves to connect ,the said toggle with a supportingwmeans notshown, an upper .threaded nipple 32 beingprovided for said attachment.' The attaching block 31 is cylindrical in shapeand provided with longitudinal water passages 33 to allow a channel for the downward How of flushing water vof the rotating cutters, through channels 34 in the two opposite keys 13 on the side of the central section 14 of the bit.

When my improved bit is to be inserted within the casing or drill stem within the welly it is lowered downwardly therein by ple 32 of the bit and allowed to pass downwardly to the end of the saidedrill stem. When lbeing-inserted within the well, the bit will be supported in the positionshown in" Fig. 2. The toggle joint connection between the supporting block 31 and the central section 14 will be collapsed, as there shown, and the lower sectionsl, of the bit, will be supported by means of the rods 20 upon the block 19. When the 'bit has reached the lower end of `the casing it will be adjusted so that the flat- -'tened head will pass between the two flanges 8`upon the drill stem. This operation may be readily performed by giving the head Aa partial rotation (provided it does not readily pass lbetween the s aid flanges- 3), until, it assumes the proper position to drop downwardly between the same, thus allowing the shoulder 4 on the shank of the bit to rest upon the upper face ofthe ianges y8. When in this position, the central section 14 may be dropped downwardly vwith some' force against thebeveled seat o10 in the`upper end ofthe shank 2 of the bit, thereby forcing the two side sections laterally and passing downwardly between the same until the plate 1-9 contactswith the upper end of the shank 2 and the shoulder 11 rests on the flange 8. When in its lowest position` the keys 13v fit within the key-ways 12 in the inner faces of the two side sections of the bit .as shownin section in Fig. 1. When in this position the weight of the attaching block 31 and the cable attached thereto will 'force the said block downwardly expanding the toggle connection between fthe block and the section 14 of the bit and will force the outer ends of thesections 27 of the toggle into the seat 26 in the'4 coupling 24. When in this position upwardmovement of the section 14 against the toggle will be impossible and the toggle will thus serve to retain the parts of the bit firmly inoperative position.

Downward force may be exerted upon the bit at any time pumping an excess of water down against the attaching block 31 in an obvious manner.

housed. in recesses in the sides of the/bit at `the point described and are provided with.

collapse thecsame. into the position shown in Fig. 2 and will exert an upwardy pull on the gether when the central section 14 is with-` drawn from between them, a coiled spring y 44 may be set in the outer roundedfface of each of the side sections of the bit at a point thereon immediately above the upper head 1 of the bit. These coiled springs 44 are a protecting ca'p 35 to prevent'sand or earth from` clogging the Aaction lof the springs. When the two side sections of the bit are forced outwardly by the central section 14 these springs are compressed, but when the central section 14 iswithdrawn, the springs 44 will serve to yforce' the said side sections toward each other 'into kthe `position shown in Fig. 2, thus allowing 'the bitto be drawn upwardly through the drill stem. 'The bit may be provided lwith reaming cutters 36, housed in the rounded sides thereof, if desired, said reaming cutters being, however, no part of 'my invention; l The flushing `water finds its way downwardly through the `channels 33 andthe channels 34 in the key 13 to the cutters on the lower end of the bit, thus serving towash away the cuttings` in the usualv manner.- The keys 13, fitting within the'key-ways 12 in the inner Vfaces of In the modified embodiment of my improved bit, illustratedA in Figs. 7 and 8, the' operative parts are identical in every way' y with that. shown in the'elmbodiment just de-v scribed, exceptas to the lower parts of the bit`itself illustrated' in these two figures.' The upper shank 2 offthe bit` is composedV of tyvo. sections to the lower'inner faces of which are detachably connected the vcutting blades 7. These blades are adapted to fit within irregular recesses 37 inthe inner.

lower faces of the section to which they 'are detachably connected by means of dovetail keys 38 fitting partly within the blades 7.

and partlywithin the sections of the shank. They are also held in ,assembled position with the sections by means of bolt-s, 39

threaded through the sections inthe manner shown in Fig. 7. The two side sections may be. expanded in the same manner as described in the embodiment shown 1n Figs.

1 to 6 by means of a central longitudinally when the upper shoulders of the blades 7 are beveled inwardly as shown at 41 on the upper outer faces thereof, upward tensionupon the rods 20, when the section14 has been removed, will cause the two side sections to move inwardly and thus allow an upward; movement of the head within the drill stem. l

' The type of bit illustrated. in this embodiment is adapted to operate in soft materials 'here simply to illustrate the fact that the novel idea constituting my invention may be applied to bits withroller cutters, such as shown in Figs. 1 to 3, inclusive, or with the fish tail blade illustrated in Figs. 7 and such as clay, sand or gumbo, and is shown Havingl thus describedmy invention, the i `advantages and objects of which will be apparent withoutv further description, what I claim as new, and desire to protect by Let- .ters Patent, is:

1. In a collapsible bit, a drill stem, a.

divided head, cutters on i the lower end thereof, a separate flattened central section, kcutters on the lower end thereof, means connected with said central section to introduce the head `downward into the' drill stem and through the lower end thereof, said central section adapted to then expand the loro headby wedging' between the sections ofA the divided head inthe manner described.l

2. In a collapsible bit, la' drill stein, a i

flanged section on the lower end thereof, a `flattened divided headthe shank of which has a cylindrical upper end forming a shouf? .der adapted to rest on said'ilange, a central section, means to force the central section into operative position to expand 'said head land cutters on said head and said central section. f l

3. In a collapsible drill bit, a divided head, comprising. three longitudinal sections, cutters on said sections, the central section adapted to be withdrawn` from said head, and means to then collapse said re- 4maining sections.,

- 4. A collapsible bit comprising two ASide y rest on said flanges, and a slidable central Y able section, two` opposite inclined side cut` ters mounted on separate sections, means to withdraw the central section from between section adaptedto wedge the side sections the side sections and means to collapse the side sections so that they may be withdrawn lfrom the drill stem.

6. vIn a collapsible bit, a

section, said central section being relatively elongated, atoggle joint pivoted thereto at its upper end, said toggle serving when eX- panded tp fix said bitf in the drill stem.

7 A collapsible bit ycomprising two side sections, means to expand the same comprising a central section, adapted to wedge between said side sections, and means to contract said bit when the central section-is Withdrawn comprising two lsprings in said side sections adapted to bear against the drill stem. f

y head comprising. two side sections and a removable central' shoulders above said' thickened walls, said head being .liattened to ypass between said walls and provided with projecting shoulders to contact with said rst mentioned shoulders to support said head" non'ro l .tatably in saiddrill stem.

`In testimony ywhereof I hereunto ailix my signature this the 19th day` of December,

- Y p 1918.` 8. In-a collapsible bit,-a` head comprising two side sections and an interfitting remov-A I GRANVILLE ALLISON HUMisoN. 

